Medieval Italian Skeleton's Surprising Diagnosis: Livestock Disease

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A sip of unpasteurized sheep or goat's milk may have spelled doom
for a medieval Italian man.

A new genetic analysis of bony nodules found in a 700-year-old
skeleton from Italy reveal that the man had brucellosis, a
bacterial infection
caught from livestock, when he died. It's not clear if the
disease killed the man, but he likely would have suffered from
symptoms such as chronic fatigue and recurring fevers, according
to the researchers who analyzed the bones.

This medieval Italian man joins many other long-dead people in
getting a postmortem diagnosis of brucellosis. Signs of the
disease have been found in skeletons from the Bronze Age and
earlier. In fact, the disease predates modern humans: In 2009,
researchers reported possible signs of brucellosis in a specimen
of the human ancestor Australopithecus africanus, who
lived more than 2 million years ago. [ 10
Deadly Diseases That Hopped Across Species ]

Disease hunters

The brucellosis-infected Italian came from Sardinia. He was
buried in a medieval village called Geridu, which was abandoned
sometime in the late 1300s, and was probably between 50 and 60
years old when he died.

Archaeologists found 32 bony nodules scattered in the man's
pelvic region, the largest about 0.9 inches (2.2 centimeters) in
diameter. Such nodules are often a sign of tuberculosis, a lung
infection caused by the
bacterium Mycobacterium tuberculosis. Tuberculosis
is the most common culprit in cases of calcified nodules, study
leader Mark Pallen, a microbial genomist at Warwick Medical
School in England, said in a statement.

Pallen and his colleagues sampled one of the nodules and
subjected it to a process called "shotgun metagenomics." Instead
of searching for a particular DNA signature, shotgun metagenomics
takes the approach of simply sampling all the DNA present, just
to see what turns up.

To the researchers' surprise, the man did not have tuberculosis.
Instead, the bony nodule held the DNA signature of the bacterium
Brucella melitensis, the microbe that causes
brucellosis.

Animal malady

Brucellosis can be transmitted from livestock to humans in
several ways. One possibility is that the man caught the disease
from direct contact with animals — perhaps while slaughtering a
sheep or delivering a newborn lamb. Or he could have gotten the
disease from drinking unpasteurized milk or eating unpasteurized
cheese. The Brucella strain that infected the man was a
close relative of modern Italian strains, the researchers found,
and sheep and goat herding have long histories in the region.

Brucellosis is also called Mediterranean fever. It still affects
more than 500,000 people around the world yearly, though
livestock vaccination and dairy pasteurization have hampered its
spread.

Today, antibiotics are used to treat people with brucellosis, and
no more than 2 percent of infected people die from the disease,
according to the Centers for Disease Control and Prevention. In
its chronic, untreated form, the disease causes muscle and joint
pain, fatigue and depression. The deadliest symptom of the
disease is endocarditis, the swelling of the lining of the
heart.

The method of diagnosing the medieval man's brucellosis could be
used to uncover other ancient diseases, the researchers said. By
not honing in on specific DNA signatures, researchers can cast a
wider net, they wrote in their report of the case published today
(July 15) in the journal mBio.

The team is now using the technique to test an array of samples,
from ancient Hungarian and Egyptian mummies to the lung tissue of
an early medieval French king, the researchers said
in a statement.

"We're cranking through all of these samples, and we're hopeful
that we're going to find new things," Pallen said.